Hose clamp

ABSTRACT

A heavy-duty clamp for a hose includes a loop, for disposing around the hose, which has two axially spaced apart looped ends. The clamp has a force generator which is connected to the two looped ends. The force generator has a bolt with a plurality of disc springs mounted thereon to allow substantially high and constant predetermined axial clamping force from the force generator under expansion and contraction of the hose over temperature operational condition of the clamp. A spacer member is mounted on the force generator between the disc spring and one of the looped ends for axially transferring the clamping force from the force generator to the looped ends. The clamping force axially draws together the looped ends so as to clamp the hose. The arrangement of the disc springs allows adjustment of the maximal allowable axial clamping force rating of the clamp.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-In-Part (C.I.P.) of patentapplication Ser. No. 10/716,566, filed on Nov. 20, 2003, now abandoned.

FIELD OF THE INVENTION

The present invention concerns clamps, more particularly to clamps foruse with hoses.

BACKGROUND OF THE INVENTION

Hose clamps are well known and widely used in industry and are practicaland reliable in applications requiring large controllable holding force.Conventionally, hose clamps include a loop of resilient material such asstainless steel, steel or plastic, which loops around the outside wallof a hose and applies a clamping force thereto. However, there existapplications where it is desirable to apply and maintain constant torqueforces against the hose clamp so as to retain high clamping forcesduring expansion and contraction of the hose during extremes oftemperature and pressure. Such temperature and pressure fluctuations aretypical for hoses used on, for example, automobile exhaust systems. Inaddition, mechanical stresses such as vibrations and dynamic stresses,normally encountered during operation of the automobile engine, aresufficient to dislodge hose clamps that are not clamped by sufficientlystrong clamping forces.

A number of designs for hose clamps exist, including:

-   -   U.S. Pat. No. 4,819,307, issued Apr. 11, 1991 to Turner for        “Hose Clamp”;    -   U.S. Pat. No. 5,010,626, issued Apr. 30, 1991 to Dominguez for        “Hose Clamp with Flanged Captive Tensioning Nut and Pivoted        Bridge Element”;    -   U.S. Pat. No. 5,299,344, issued Apr. 5, 1994 to Oetiker for        “Reinforcing Arrangement for Open Hose Clamps, Especially        Screw-Type Hose Clamps”;    -   U.S. Pat. No. 5,720,086, issued Feb. 24, 1998 to Eliasson et al.        for “Clamping Collar”; and    -   WO 01/27516A1, published Apr. 19, 2001 to Dominguez for        “Improved Clamp with a Tightening Screw”.

These hose clamps, however, suffer from a number of importantdisadvantages. Most clamps use a bolt that applies a clamping forcedirectly against a shoulder of a loop end. During application of hightorque forces during the clamping operation, the force direction may notbe axially applied in a constant manner due to deformation of theshoulder by the clamping forces. This non-constant application of torqueforce across the loop end may be prone to failure during temperaturerelated expansion and contraction of the hose.

Disadvantageously, most hose clamp designs use T-bolts and coil springsmade of steel, which is prone to corrosion and freezing under normalhot/cold and humid operation conditions, thus decreasing the clampingtorque of the clamp over time and severely limiting the life cyclethereof. In addition, most coil springs limit the amount of force thatcan be applied during clamping, especially when corrosion resistantspring material is used such as stainless steel. For example, themaximum applicable torque load over an existing enlarge coil springclamp of a specific hose diameter, such as the clamp part No.BRZ-B9226-0406 from Breeze Industrial Products Corporation™, is about100 in-lbs (at full compression of the coil spring) to hold a maximuminternal hose pressure of about 55-60 psi (pound per square inch) and160 in-lbs at failure (physical breakage of the clamp); as depicted bycurve 90 of FIG. 12. In order to sustain much higher hose internalpressure up to and above 100 psi by increasing this maximum workabletorque load up to and above 150 in-lbs, or the maximal load rating ofthe clamp, the coil spring would need to be of an outer diameter ofabout three times (3×) than that of an equivalent loading capacity discspring, such as about at least two inches (2 in), which could be aslarge as the hose itself and would therefore prove unpractical andunusable.

Other types of clamps use disc springs made of stainless steel ortungsten alloys to improve the load constancy over temperature induceddeflection, irrespective of any maximal load and corrosionconsiderations. Other types of hose clamps use worm gears to applytorque forces to the clamp, which worm gears may be unsuitable inoperations requiring constant high clamping torque. In some cases, toavoid damage or rupture of the clamp during operation, it would beadvisable to have a better control the constancy of the clamping torqueover operational conditions of the clamp.

Thus there is a need for an improved heavy-duty hose clamp that can beused to apply and maintain substantially constant high clamping forcesover operational life conditions thereof.

SUMMARY OF THE INVENTION

The present invention is directed towards a solution to the aforesaidproblems by providing a heavy-duty hose clamp with a novel spacer thatallows a user to axially apply constant significant torque forces duringa clamping operation, especially because of the curved portions of thebolt head and nut freely pivotally engaging respective looped ends ofthe loop or band. A novel combination of the spacer, capture nuts and anarrangement of a number of axially aligned disc springs maintainconstant high clamping forces around the hose. The capture nuts areshaped to allow inward transfer of the clamping forces from a bolt tolooped ends to close the gap therebetween and to reduce the clamp looparound the hose. Advantageously, the clamp significantly increases themagnitude of working clamping torque that is safely available to theuser, easily up to about 420 in-lbs, and the adjustment thereof,depending on the disc arrangement as well as the geometricalconfiguration of the disc. The hose clamp of the present invention,especially because of the use of disc springs, is simple to operate andis manufactured from inexpensive, lightweight and readily availablecorrosion resistant materials, such as stainless steel or the like. Thehose clamp can be custom made to fit many hose dimensions, up to about35 inches in diameter, and uses readily available tools to apply theclamping forces to the bolt. In addition, the user can select manycombinations of the disc springs' orientation and quantity to apply avariety of different clamping deflections for the clamping operationrequired. Also, varying the quantity of disc springs allow to control ofthe amount of displacement between the two looped ends for asubstantially constant clamping torque over the amount of hosecircumferential variation (contraction/expansion). Varying the physicalcharacteristics of the disc springs such as the disc thickness allowsdetermining the maximum clamping torque capability of the hose clamp.

In a first aspect of the present invention, there is provided aheavy-duty clamp for a hose, the clamp including a loop for disposingaround the hose and having first and second axially spaced apart loopedends, the clamp comprises: a force generator, for drawing together thefirst and second looped ends, and connected to the first and secondlooped ends to apply a predetermined axial clamping force to the loopwithin a maximal axial clamping force rating of said clamp, the forcegenerator including a bolt and a plurality of disc springs mountedthereon and made out of steel alloy material so as to allow saidpredetermined axial clamping force to be substantially high and constantunder circumferential expansion and contraction of the hose overtemperature operational condition thereof; a spacer member mounted onthe force generator between the plurality of disc springs and the firstlooped end and axially transferring the clamping force from the forcegenerator to the first and second looped ends, the clamping forceaxially drawing together the first and second looped ends so as to clampthe hose; and means for adjusting said maximal axial clamping forcerating, said adjusting means including said plurality of disc springsbeing stacked against one another into one of a plurality of discarrangements.

In one embodiment, the one of a plurality of disc arrangements includessaid plurality of disc springs being arranged in series.

In another embodiment, the one of a plurality of disc arrangementsincludes said plurality of disc springs being arranged in parallel.

In a further embodiment, the one of a plurality of disc arrangementsincludes said plurality of disc springs being arranged in pairs ofparallel disc springs, said pairs being arranged in series.

In one embodiment, each said disc spring has a conical shapeconfiguration defined by a disc thickness and a disc conical angle, saidadjusting means further including said plurality of disc spring beingselectable from one of a plurality of disc configurations.

In one embodiment, the first looped end includes a first outer face anda first inner face, and the second looped end includes a second outerface and a second inner face, the first and second outer faces beingangled inwardly towards each other and the first and second inner facesbeing curved and disposed inwardly towards each other. The first loopedend includes first and second holes located in the respective firstouter and inner faces and the second looped end includes third andfourth holes located in the respective second outer and inner faces, theholes being axially aligned with each other.

Typically, the bolt has a first bolt end and a second bolt end, andpasses through the first, second, third and fourth holes. The boltincludes a threaded portion and a non-threaded portion, the non-threadedportion extending through and away from the first looped end. Theplurality of disc springs and the spacer member are slidably mounted onthe non-threaded portion, the plurality of disc springs being locatednear the first bolt end.

Typically, the force generator further includes a first capture nutmounted in the first looped end and a second capture nut mounted in thesecond looped end. The first capture nut includes a non-threaded axialbore. The second capture nut includes a threaded axial bore. The firstand second capture nuts each includes a curved end and a stem portion.

Typically, the spacer member includes a cylindrical collar with an axialbore sized to accommodate the bolt therein, the cylindrical collarhaving a force receiver end and a force transfer end.

Typically, the stem portion of the first capture nut is disposed towardsthe first hole of the first looped end and abuts the force transfer end.

Typically, the second looped end includes one hole that is axiallyaligned with the first and second holes of the first looped end.

In one embodiment, the force generator is a T-bolt that passes thoughthe first and second holes of the first looped end and through the onehole of the second looped end, the T-bolt having a T-bolt end and athreaded bolt portion on which is movably mounted a nut, the T-bolt endbeing located in the second looped end. The nut includes a smooth outersurface on which are mounted the disc springs and a threaded borethrough which the T-bolt passes.

Typically, the second bolt end includes a nut stop. The nut stop isintegral with the stem portion of the second capture nut.

Typically, the first hole of the first looped end is larger than thesecond hole of the first looped end.

Typically, the clamp loop, when viewed in cross section, includes aplanar portion and two ends that are angled away from the surface of thehose.

Typically, a plate is hingeably connected to the first looped end isadapted to be in a circumferentially aligned relationship with the loopbetween the first and second loop ends when the clamp is disposed aroundthe hose, thereby substantially clamping a section of the hose locatedbetween the first and second looped ends and bridging a gaptherebetween.

Typically, the plate includes a guide portion for guiding the moveablefirst and second looped ends when moving towards and away from eachother during clamping and under circumferential variation of the hoseduring operation thereof.

Typically, the plurality of disc springs are made out of corrosionresistant material.

Typically, the maximal axial clamping force rating of said clamp iswithin the range of about 100 in-lbs and about 420 in-lbs, preferablywithin the range of about 150 in-lbs and about 220 in-lbs.

Other objects and advantages of the present invention will becomeapparent from a careful reading of the detailed description providedherein, with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects and advantages of the present invention will becomebetter understood with reference to the description in association withthe following Figures, wherein:

FIG. 1 is a perspective view of an embodiment of a heavy-duty hose clampof the present invention;

FIG. 1 a is a cross section view taken along line 1 a-1 a of FIG. 1;

FIG. 2 is a side view of the hose clamp of FIG. 1;

FIG. 3 a is a partial cutaway view of 10 series pairs of disc springsarranged in series and cooperating with a bolt of FIG. 1;

FIG. 3 b is a perspective view of a spacer member;

FIG. 4 a is a perspective view of a looped end;

FIG. 4 b is a side view of a looped end with a capture nut locatedtherein;

FIG. 5 a is a side view of one capture nut;

FIG. 5 b is an end view taken along line 5 b of FIG. 5 a;

FIG. 5 c is a side view of a unitary capture nut/Stover nut;

FIG. 5 d is a side view of a unitary capture nut/Nylon insert;

FIG. 6 a is a side view of another capture nut;

FIG. 6 b is an end view taken along line 6 b of FIG. 6 a;

FIGS. 7 a to 7 f are simplified section views of a number of discsprings illustrating different arrangements thereof;

FIG. 8 is a top view of a hingeable plate;

FIG. 9 is a side view of a second embodiment of the hose clamp;

FIG. 9 a is a perspective view of a T-bolt engaged a looped end;

FIG. 9 b is a side view of FIG. 9 a;

FIG. 9 c is a partial cutaway side view of a nut of FIG. 9;

FIG. 10 is a side view of a third embodiment of the hose clamp;

FIG. 11 is a side view of a fourth embodiment of the hose clamp;

FIG. 12 is a graphical representation of the internal hose pressuresustainable by a heavy duty clamp of the present invention and by aconventional coil spring clamp in function of the clamping torqueapplied thereon; and

FIG. 13 is a graphical representation of the spring deflection allowedby a heavy duty clamp of the present invention with different discspring arrangements and by a conventional coil spring clamp in functionof the clamping torque applied thereon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of a hose clamp 10 of the present invention is shown inFIG. 1. Broadly speaking, the clamp 10 includes a clamp loop 12, twomoveable looped ends 14 and 16, a force generator 18, a separator orspacer member 20, at least one and preferably a plurality of pairs ofdisc springs 22, and a hingeable plate 24; all typically made out ofsteel alloy material and preferably a corrosion resistant material suchas stainless steel or the like.

Referring now to FIGS. 1 and 2, in a typical application, an item forclamping, for example a high-pressure, heavy-duty hose 26 is received inthe clamp loop 12. The clamp loop 12 is disposable axially along a mainaxis 28 of the hose 26 and annularly around the hose 26. The clamp loop12 is typically made of stainless steel, which has sufficient resilienceto withstand high operating torque forces applied thereto. The clamploop 12 includes the two moveable looped ends 14 and 16, one of whichwill now be described in detail with reference to FIGS. 1 and 2. Thelooped end 14 has an inner face 29 and an outer face 30. The inner face29 is continuous with an inner periphery surface 32 of the clamp loop12. The outer face 30 is continuous with an outer periphery surface 34of the clamp loop 12 and is angled inwardly. Typically, the clamp loop12 is machined from a single piece of material, the ends of which arelooped back on themselves and connected to the outer periphery surface34 by a securing means 35 known to those skilled in the art. An exampleof such securing means include stamping, welding or staples and thelike. In a default, non-clamping configuration, the inner faces 29 areaxially spaced apart from each other and define a gap therebetween. Theclamp loop 12 materials are sufficiently resilient to allow the moveablelooped ends 14 and 16 to move towards each other, when subjected toclamping forces. In a clamping configuration, the hose 26 is clampedbetween the inner periphery surface 32 of the clamp loop 12 by the forcegenerator 18 acting against the moveable looped ends 14 and 16.

As best illustrated in FIG. 1 a, the clamp loop 12, in a clampingconfiguration when viewed in cross section, includes two ends 13 thatare curved away from the hose 26 surface and a generally planar portion15 which rests against the surface of the hose 26. The two curved ends13 prevent the clamp loop 12 from biting into the hose 26 duringclamping and reduce damage to the surface of the hose 26.

Referring now to FIGS. 4 a and 4 b, each of the looped ends 14 and 16has two openings or holes 36 and 38 disposed therein. The holes 36 and38 are axially aligned with each other and with the holes of the othermoveable looped end. The holes 36 and 38 have an axis 40, which arealigned generally perpendicularly to the main axis 28 of the hose 26during clamping. The hole 36 is disposed outwardly, whereas the hole 38is disposed inwardly towards the gap. The hole 36 is generally of alarger size than hole 38 and is elliptical to allow the user to move theforce generator 18 up and down to allow the force generator to bealigned with the hole 38. In addition, each of the looped ends 14 and 16include a second opening 42, which has a second opening axis 44 that isgenerally perpendicular to the axis 40 and which is generally parallelto the main axis of the hose 26. The moveable looped ends 14 and 16 eachhave an inner surface 46 that defines the second opening 42. The innersurface 46 has a curved portion 48 and a generally planar portion 50.The curved portion 48 is disposed inwardly towards the other looped endand the gap there between.

Referring to FIGS. 2 and 3 a, the force generator 18 passes through theholes 36 and 38 and cooperates with one of the outer faces 30 to applyan inwardly directed force thereto to draw the moveable looped ends 14and 16 towards each other. In this embodiment, the force generator 18 isa bolt 52 that is sized to pass through each of the holes 36 and 38. Thebolt 52 typically includes threads along a threaded portion 53 and anon-threaded smooth portion 55 on which the disc springs 22, that form ameans for adjusting a displacement of the two looped ends 14, 16relative to one another under the predetermined clamping force and undercircumferential variation of the hose 26 over its operational conditionrange, are slidably mounted to allow for their smooth compression andexpansion. The bolt 52 also includes a first bolt end 74 and a secondbolt end 54.

Referring to FIGS. 2, 5 a, 5 b, 6 a and 6 b, the force generator 18 alsoincludes two capture nuts 56 and 58 are positioned in the secondopenings 42. Both capture nuts 56 and 58 cooperate with the innersurface of the looped ends 14, 16 to generate the inwardly directedforces thereon. The capture nut 56 has a non-threaded axial bore 57,whereas the capture nut 58 has a threaded axial bore 59, both bores 57and 59 are sized to allow engagement with the bolt 52. The bolt 52, inthe clamping configuration extends through each of the bores 57 and 59,the end 54 of the threaded bolt extends outwardly from capture nut 58.Both capture nuts 56 and 58 include a curved end portion 60 and a stemportion 62. The curved end portion 60 cooperates with the curved portion48 of the looped end 14, 16 and is disposed towards the gap. The stemportion 62 is disposed towards the planar portion 50 of the looped ends14, 16. The stem 62 of the capture nut 56, located in the looped end 14,is cooperable with the spacer 20 to receive the inwardly directed forcethereagainst. Both capture nuts 56 and 58 have elongate sides 61 and ashorter side 63. Recesses 65 extends inwardly from the shorter side 63of the capture nut 56 to allow access room to the pins 76 of thehingeable plate 24 for the pivoting thereof, as further explainedhereinbelow.

As shown in FIGS. 5 c and 5 d, a friction nut stop 62 a in the form of aStover nut or a nylon insert nut, respectively, or an abutting nut stopas a lock nut (not shown) may be added to the bolt end 54 after torquingto damp against major vibrations, and rests against the stem 62 of thecapture nut 58. Alternatively, the capture nut 58 and the nut stop 62 amay be a unitary piece 58 a, in which the nut stop 62 a, Stover nut andnylon insert nut, are integral with the stem 62.

Referring to FIGS. 2, 3 a, and 3 b, the spacer member 20 of the presentinvention is axially aligned with the holes 36 and 38 in the looped ends14, 16. The spacer member 20 is orientated towards the outer face of thelooped end 14 to axially transfer the inwardly directed force from thebolt 52 to move the moveable looped ends 14, 16 together. The spacermember 20 is a cylindrical collar 64 with an axial bore 66 of sufficientsize to slide over a non-threaded portion of the threaded bolt 52. Thecylinder 64 has a force receiver end 67 and a force transfer end 68. Theforce receiver end 67 abuts a first generally convex outer face 70 ofone of the disc springs 22. The force transfer end 68 abuts the stemportion 62 of the capture 56. Both the ends 67 and 68 have planarsurfaces for contacting the stem 62 and the first face 70 of the discspring 22.

Each disc spring 22 essentially has a conical shape configurationdefined by a disc thickness T and a disc conical angle A, as shown in arest state in FIG. 7 a, which determines the required maximal axialcompressive force to fully compress the spring 22 in a flattened andfully deflected state (not shown). When stacked against one another intoa disc arrangement, a plurality of disc springs 22 require an overallmaximal axial compressive force to fully deflect the disc arrangementand providing a corresponding overall deflection, depending on the discarrangement. Accordingly, the clamp 10 of the present invention includesa means for adjusting the maximal axial clamping force rating thereof bythe selection of one from a plurality of possible disc arrangements. Theselection of the disc shape configuration of the disc springs 22 formingthe disc arrangement is also part of the adjusting means. For a sameconical angle A and disc inner and outer diameters, the larger the discthickness T is the larger the required maximal axial compressive forcerating is.

Now referring to FIGS. 7 a to 7 f, there are shown different discarrangements. In FIG. 7 a, the disc spring 22 has a predeterminedmaximal deflection when subjected to its maximal axial compressiveforce. The series disc arrangements of FIGS. 7 c and 7 e of two and fourdisc springs 22 require the same maximal axial compressive force tofully compress or flatten the disc arrangements, while the maximaldeflections of the arrangements would substantially be two and fourtimes the maximal deflection of the single disc spring 22 of FIG. 7 a,respectively.

Similarly, the series disc arrangements of FIGS. 7 b, 7 d and 7 f oftwo, four and eight disc springs in pairs of parallel disc springs(two-by-two in parallel) require about twice the maximal axialcompressive force of the single disc spring 22 to fully compress orflatten the disc arrangements (because of the pairs of parallel discsprings), while the maximal deflections of the arrangements wouldsubstantially be one, two and four times the maximal deflection of thesingle disc spring 22 of FIG. 7 a, respectively.

Referring to FIGS. 3 a and 7 a to 7 f, one can understand that with thedisc springs 22 axially aligned and stacked against one another with thespacer member 20 and the bolt 52 to transfer the inwardly directedclamping force to the moveable looped ends 14, 16, many possible maximalclamping loads can be achieve depending on the disc configuration anddisc arrangement thereof.

In the embodiment shown in FIGS. 1, 2 and 3 a, a number of the discsprings 22 are arranged in a series arrangement in pairs along thenon-threaded portion of the bolt 52. When a selected number of N (20disc springs shown in FIGS. 1, 2 and 3 a) disc springs 22 are arrangedin series, the maximal axial clamping torque force required to flatten(to render flat) all disc springs is the same as the one required toflatten a single disc spring, with an overall compressive deflectionbeing approximately N times the one obtained with a single disc spring22. Each pair of the disc springs 22 includes the first face 70, anopposite second face 72 and a central space 73 defined by generallyconcave inner faces 75. The second face 72 cooperates with the bolt endhead 74 to receive the clamping force thereagainst. When fullydeflected, the central space 73 becomes substantially inexistent or nullsince the opposed second faces 72 touch one another.

From the above, the disc springs 22 can be used in many differentarrangements (as shown in FIGS. 7 a to 7 f) and have sufficientresilience to contract against each other when forces are applied to oneor both faces 70 and 72. One skilled in the art will recognize that onedisc spring 22 may be used with the bolt 52 such that either of thefirst or second faces 70, 72 and the inner face 75 receives the clampingforce from the bolt end head 74.

As shown in FIG. 12, there is shown in curve 92 (same arrangement as forcurve C8 of FIG. 13), for a typical heavy-duty clamp of the presentinvention similar to the one shown in FIGS. 1 and 2 but with eight (8)pairs of single disc springs 22, the hose internal pressure that issafely sustainable by the clamp as a function of the clamping torqueforce applied thereto to secure the hose 26. For example, with asecuring applied clamping torque force of about 200 in-lbs, the clampwill sustain a hose internal pressure up to about 200 psi. The beginningof the flat portion of the curve provide the maximal clamping torquerating F at which the disc arrangement is fully deflected, while the endthereof shows the ultimate clamping torque force U at which the clampbreaks apart or fails. Curve 90 explicitly shows the same torquelimitations F′, U′ of a conventional coil spring clamp, which are wellbellow the ones of the present clamp 10. In fact, it would not bepractically feasible to obtain the same clamping torque range as for thedisc spring clamp 10 of the present invention with the conventional coilspring clamp unless the coil spring increases to a few inches indiameter.

Typically, as illustrated by an actual tested example of FIG. 12,conventional hose clamps have an ultimate clamping torque rating U′ (atclamp failure) of about 150 in-lbs torque working force with a workablemaximal clamping torque rating F′ (at full deflection or compression ofcoil spring) of about 100 in-lbs (as illustrated with curve 90 of FIG.12), whereas with the hose clamp 10 of the present invention, thisultimate clamping torque rating U increases significantly up to about420 in-lbs with a workable maximal clamping torque rating F of about 220in-lbs (as illustrated with curve 92 of FIG. 12). At clamping torquevalues of less than 100 in-lbs, the clamp of the present invention(curve 92) is slightly less efficient than the conventional coil springclamp simply because of the wider loop 12 providing less pressure bysquare inch at the loop-hose contact interface; the wider loop beingrequired to enable the higher efficient clamping torque range of theheavy-duty clamp 10.

When clamping a hose 26 with the clamp 10 of the present invention, onecan select the predetermined clamping force to use based on therequirements and the operational condition of the hose and the clamp,namely temperature and humidity operational ranges over time.Accordingly, for a same clamping force or torque, the more bolt lineardisplacement variation (spring deflection) and therefore circumferentialvariation of the hose will be allowed under operational condition whenmore disc springs are used, as seen from curves C6, C8 and C10 of FIG.13 representing 6, 8 and 10 single (or series) pairs of disc springs inseries, respectively (C8 being 4 times the arrangement shown in FIG. 7e, C10 being the arrangement shown in FIG. 2). Hence, by varying thequantity of disc springs, the linear displacement of the two looped ends14, 16 during the hose circumferential variation can be adjusted, andthe slightly varying clamping force controlled. Curve D5 represents aclamp 10 with a disc arrangement of five (5) pairs of double discsprings 22 in series (5 times the arrangement shown in FIG. 7 d).Although this latter arrangement includes the same quantity of discsprings as the C10 curve, its clamping torque rating F″ is about twicethat (F) of C10 (because of double or parallel disc springs), 420 in-lbsviz 220 in-lbs, with half the overall maximal deflection (because offive (5) pairs instead of ten (10) for C10).

In the case in which the disc arrangement would include a mix of singledisc pairs and double disc pairs in series, its behavior of wouldprovide a larger deflection rate (more deflection per unit change ofclamping torque) at the low torque end of the curve than the same end ofthe corresponding curve representing an arrangement with only doubledisc pairs in series, while the end of both curves would have anessentially similar deflection rate relative to one another since allthe single disc pairs would have already been fully deflected in thatportion of the curve.

More specifically, when the hose 26, after clamping with a predeterminedclamping force P (which could be anywhere along the torque axis of FIG.13), expands outwardly such as during operations when the hose 26carries high temperature, high pressure fluids such as water, steam, oroil, the outward expansion forces act against the inner peripherysurface 32 of the clamp loop 12 and act against the inwardly directedclamping force P to maintain a substantially constant clamping force.The hose expansion will make the clamping torque to slightly increase,as illustrated when moving toward the right hand side on any curve C6,C8 or C10 from the force P of FIG. 13. The disc springs 20 havesufficient resilience to deform during the expansion such that the sizeof the central space 73 decreases thereby taking up the increase in theinwardly directed force of the force generator 18 to compensate for theexpansion of the hose 26 and the increasing distance between the twolooped ends 14, 16.

Similarly, as the hose 26 cools, it will contract and the central space73 of the disc springs 22 will increase in size to compensate for thedecreasing distance between the two looped ends 14, 16, the disc springs22 attaining their dish-like appearance and the force generator 18 willretain its substantially constant predetermined clamping force P againstthe disc springs 22 and against the hose 26; as illustrated when movingtoward the left hand side on any curve C6, C8 or C10 from the force P ofFIG. 13. Curve 94 of FIG. 13 shows the spring deflection of aconventional coil spring clamp at its relatively low clamping torques.

Referring to FIGS. 1, 2 and 8, the hingeable plate 24 is hingeablyconnected to one of the looped ends 14. The plate 24 is continuous, orcircumferentially aligned, with the inner clamp loop periphery 32 andincludes two inward projections 76. The plate 24 may also include asingle bar in place of the two projections 76, which may be positionedacross the plate to lock the plate 24 in place during clamping. Thehingeable plate 24 acts as a bridge across the gap and includes a guideportion 78 located on an outer face 80 for guiding the moveable loopedends 14 and 16 along a path of travel towards and away from each otherduring clamping. The guide portion 78 includes two opposing edge walls82 axially aligned with the openings 36 and 38. The plate 24 allows theuser a means by which the looped ends 14 and 16 can be aligned andallows maneuverability of the clamp 10 along the hose 26 beforeclamping. The plate 24 may optionally be swung out of alignment (asshown in outline in FIG. 2) with the looped ends 14 and 16 should theuser need to completely disengage the hose clamp 10 from the hose 26.

Operation

Referring to FIGS. 1 and 2, generally, the hose clamp 10 is supplied ina default configuration with the bolt 52 disconnected from the loopedends 16 and 18 and the capture nuts 56 and 58. Considering the initialtorque P that is required and the torque variation that is acceptablefor an expected amount of circumferential variation(contraction/expansion) of the hose over its operational condition overtime, the user selects the appropriate number of disc springs 22 andadds them to the shaft of the bolt 52 and slides the spacer member 20onto the bolt 52 shaft. The bolt 52 is positioned adjacent thenon-threaded bore 57 of the capture nut 56 and with the hose 26 to beclamped in place snuggly against the inner periphery 32, the operatoraligns the bolt end 54 with the hole 38 and the threaded bore 59 of thecapture nut 58. The user then applies a turning force to the bolt end 74causing the moveable ends 14 and 16 to slide along the plate 24 towardseach other thereby tightening the clamp 10 around the hose 26 to therequired torque. Alternatively, the clamp 10, with the disc springs 22,the spacer member 20 and capture nuts 56 and 58 aligned, is slipped overthe hose 26, which is connected to a fluid source (not shown). The clamp10 is then tightened as described.

Alternatives

The first embodiment of the hose clamp 10 is useful in many clampingoperations. There may be applications, such as for hoses in areas oflimited accessibility that require the use of a T-bolt in combinationwith the disc springs, the spacer member and a hingeable plate which haslimited movement. A second embodiment 100, illustrated in FIG. 9,operates in essentially the same way as the first embodiment 10 andincludes a clamp loop 102, a force generator 104, a spacer member 106, acapture nut 107, disc springs 108, and two moveable looped ends 110 and112. The differences between 10 and 100 will now be described withreference to FIGS. 9 a, 9 b and 9 c.

The looped end 112 includes a hole 114, an opening 116, a generallyplanar outward face 118 and a curved inward face 120. A shaped innersurface 122 defines the second opening 116, a planar portion 124 ofwhich lies adjacent a T-bolt end 126. During clamping, the T-bolt end126 pushes against a curved surface 128 of the second opening 116 andinwardly transfers the clamping force as the force generator 104 actsinwardly against the looped end 110, as described for the clamp 10. Theforce generator 104 includes an elongated threaded bolt portion 130 anda nut 132 mounted on the bolt threads.

As best illustrated in FIG. 9 c, the nut 132 has a smooth outer surface134, on which the disc springs 108 (only two are shown) are mounted forsliding and abutment against the spacer member 106, and a threaded bore(not shown) through which the bolt 130 passes during clamping. Unlikewith the clamp 10, turning the bolt 130 causes the disc springs 108 tomove along the smooth surface 134 of the nut 132 towards the spacermember 106, while the nut 132 moves down the bolt 130 shaft. The nut 132may alternatively include a nut head 133 that is separate from a smoothsurfaced sleeve 135 and still work the same way as the unitary nut 132.

A third embodiment of a hose clamp 200 is illustrated in FIG. 10 andoperates in the same way as the first embodiment of the hose clamp 10.There may be clamping applications that require the use of a hose clamploop that has two gaps between two sets of movable looped ends. The hoseclamp 200 includes first and second clamp portions 202 and 204, whichtogether form a clamp loop 206. Two sets of moveable looped ends 208 and210 are moveable by two force generators 212 with two spacer members214.

A fourth embodiment of a hose clamp 300 is illustrated in FIG. 11 and isstructurally similar to the second embodiment 200. The hose clamp 300includes first and second clamping portions 302 and 304, which togetherform a clamp loop 306. Two T-bolts 308 are used together with two setsof moveable looped ends 310 and 312, which are moveable by two forcegenerators 314 with two spacer members 316.

While a specific embodiment has been described, those skilled in the artwill recognize many alterations that could be made within the spirit ofthe invention, which is defined solely according to the followingclaims.

1. A heavy-duty clamp for a hose, the clamp including a loop fordisposing around the hose and having first and second axially spacedapart looped ends, the clamp comprising: a force generator, for drawingtogether the first and second looped ends, and connected to the firstand second looped ends to apply a predetermined axial clamping force tothe loop within a maximal axial clamping force rating of said clamp, theforce generator including a bolt and a plurality of disc springs mountedthereon and made out of steel alloy material so as to allow saidpredetermined axial clamping force to be substantially high and constantunder circumferential expansion and contraction of the hose overtemperature operational condition thereof; a spacer member mounted onthe force generator between the plurality of disc springs and the firstlooped end and axially transferring the clamping force from the forcegenerator to the first and second looped ends, the clamping forceaxially drawing together the first and second looped ends so as to clampthe hose; and means for adjusting said maximal axial clamping forcerating, said adjusting means including said plurality of disc springsbeing stacked against one another into one of a plurality of discarrangements.
 2. The clamp, according to claim 1, wherein said one of aplurality of disc arrangements includes said plurality of disc springsbeing arranged in series.
 3. The clamp, according to claim 1, whereinsaid one of a plurality of disc arrangements includes said plurality ofdisc springs being arranged in parallel.
 4. The clamp, according toclaim 1, wherein said one of a plurality of disc arrangements includessaid plurality of disc springs being arranged in pairs of parallel discsprings, said pairs being arranged in series.
 5. The clamp, according toclaim 1, wherein each said disc spring has a conical shape configurationdefined by a disc thickness and a disc conical angle, said adjustingmeans further including said plurality of disc spring being selectablefrom one of a plurality of disc configurations.
 6. The clamp, accordingto claim 1, in which the first looped end includes a first outer faceand a first inner face, and the second looped end includes a secondouter face and a second inner face, the first and second outer facesbeing angled inwardly towards each other and the first and second innerfaces being curved and disposed inwardly towards each other.
 7. Theclamp, according to claim 6, in which the first looped end includesfirst and second holes located in the respective first outer and innerfaces and the second looped end includes third and fourth holes locatedin the respective second outer and inner faces, the holes being axiallyaligned with each other.
 8. The clamp, according to claim 7, in whichthe bolt has a first bolt end and a second bolt end, the bolt passingthrough the first, second, third and fourth holes.
 9. The clamp,according to claim 8, in which the bolt includes a threaded portion anda non-threaded portion, the non-threaded portion extending through andaway from the first looped end, the plurality of disc springs and thespacer member are slidably mounted on the non-threaded portion, adjacentthe first bolt end.
 10. The clamp, according to claim 9, in which theforce generator further includes a first capture nut with a non-threadedaxial bore mounted in the first looped end and a second capture nut witha threaded axial bore mounted in the second looped end.
 11. The clamp,according to claim 10, in which the spacer member includes a cylindricalcollar with an axial bore sized to accommodate the bolt therein, thecylindrical collar having a force receiver end and a force transfer end.12. The clamp, according to claim 11, in which the first and secondcapture nuts each includes a curved end and a stem portion, the stemportion of the first capture nut being disposed towards the first holeof the first looped end and abuts the force transfer end.
 13. The clamp,according to claim 7, in which the second looped end includes one holethat is axially aligned with the first and second holes of the firstlooped end.
 14. The clamp, according to claim 13, in which the forcegenerator is a T-bolt that passes though the first and second holes ofthe first looped end and through the one hole of the second looped end,the T-bolt having a T-bolt end and a threaded bolt portion on which ismovably mounted a nut, the T-bolt end being located in the second loopedend.
 15. The clamp, according to claim 14, in which the nut includes asmooth outer surface on which are mounted the plurality of disc springsand a threaded bore through which the T-bolt passes.
 16. The clamp,according to claim 12, in which the second bolt end includes a nut stop.17. The clamp, according to claim 16, in which the nut stop is integralwith the stem portion of the second capture nut.
 18. The clamp,according to claim 6, in which the first hole of the first looped end islarger than the second hole of the first looped end.
 19. The clamp,according to claim 1, in which the clamp loop, when viewed in crosssection, includes a planar portion and two ends that are angled awayfrom the surface of the hose.
 20. The clamp, according to claim 1, inwhich a plate is hingeably connected to the first looped end is adaptedto be in a circumferentially aligned relationship with the loop betweenthe first and second loop ends when the clamp is disposed around thehose, thereby substantially clamping a section of the hose locatedbetween the first and second looped ends and bridging a gaptherebetween.
 21. The clamp, according to claim 20, in which the plateincludes a guide portion for guiding the moveable first and secondlooped ends when moving towards and away from each other during clampingand under circumferential variation of the hose during operationthereof.
 22. The clamp, according to claim 1, in which the plurality ofdisc springs are made out of corrosion resistant material.
 23. Theclamp, according to claim 1, in which the maximal axial clamping forcerating of said clamp is within the range of about 100 in-lbs and about420 in-lbs.
 24. The clamp, according to claim 23, in which the maximalaxial clamping force rating of said clamp is within the range of about150 in-lbs and about 220 in-lbs.